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Hexa- O -methyl- scyllo -inositol was synthesized and its crystal structure was determined by X-ray diffraction. As predicted by calculations, each oxygen-methyl bond eclipses the adjacent carbon-hydrogen bond. NMR studies show that the same conformation predominates in solution.

The composition of aldohexoses, aldopentoses, and hexuloses has been determined by 13C NMR spectroscopy in dimethyl sulfoxide (Me2SO) solution.

Alditols form stronger complexes with Nd3+, Sm3+, and Eu3+ than with La3+ cations, but weaker ones with the higher lanthanides. There is a clear relationship between ionic radii and stability constants. Chromatographic ion-exchange columns can be smaller when prepared with Nd3+ rather than the usual Ca2+ columns. Galactitol, alone amongst the hexitols, can form 1:2 complexes with lanthanide ions. The crystal structure of galactitol·2PrCl3·14H2O has been determined.

3- C -Hydroxymethyl- d -glucose, when heated with dilute acids, rapidly forms 96% of the 1,3 1 -anhydride. 3- C -Hydroxymethyl- d -xylose, - l -lyxose, and - d -ribose each form an equilibrium that contains similar anhydrides to a progressively lesser extent. Each of these branched-chain sugars has six cyclic forms in aqueous solution and their proportions have been determined.

The molecular structures of the title heptitols were determined by X-ray crystallography, using direct methods, and refined to final residual parameters of R = 0.037 and 0.039, respectively. Each compound adopts a bent conformation. For α-sedoheptitol ( 1 ), this is not the expected conformation (with O-6 in the extended planar position). Instead, 1 adopts a conformation with a 1,3- parallel interaction between O-4 and C-7.

Contrary to statements in the literature, Cu2+ ions form only weak complexes with polyols. At pH > 5, however, strong complex formation is observed which is attributed to [Cu2(OH)2]2+ or similar binuclear ions. The formation of tetradentate complexes is postulated with compounds having four hydroxyl groups in suitable steric relationship, especially alditols.

It is postulated that, in the epimerization of glucose in alkaline solution catalyzed by Ca 2+ ions (and other cations of similar size), the intermediate is a complex of the cation with O-1, O-2, O-3 and O-4 of the sugar and that the reaction proceeds, like the Bilik reaction, with rearrangement of the carbon chain.

myo-Inositol 4,6-carbonate, a compound having three syn-axial hydroxyl groups, was synthesized in four steps suitable for gram-scale preparation. It readily forms complexes with cations.

Several cyclohexanepentols have been synthesized from inositols by blocking all but one hydroxyl group, converting the free hydroxyl group into its S -methyl dithiocarbonate, and treating it with tributylstannane. Suitable blocking-groups are methyl, benzyl, and methylthiomethyl ethers, and acetals. One cyclohexanepentol was prepared by the reductive deamination of an aminodeoxyinositol.

On acid-catalyzed equilibration in aqueous solution, three aldoheptoses, d -glycero- l -manno-, d -glycero- l -allo-, and d -glycero- l -altro-heptose, give 15, 54, and 98%, respectively, of the 1,6-anhydropyranose, a much higher proportion than is formed from the homomorphous aldohexoses. This is another example of the greater tendency of secondary, compared to primary, hydroxyl groups to participate in the formation of cyclic acetals.

The relative rates of protium-deuterium exchange, catalysed by deuterated Raney nickel in deuterium oxide, in various positions of 1,6-anhydrohexopyranoses and -furanoses have been studied. Conditions have been found under which 1,6-anhydro-β- D -galactopyranose may be labelled on C-3 and 1,6-anhydro-α- D -galactofuranose on C-2.

Three-dimensional, single-crystal, X-ray diffraction methods were used to determine the structure of the calcium chloride complex of α - d -allopyranosyl α - d -allopyranoside. The crystal is monoclinic with cell dimensions: a = 16.262(5), b = 8.345(5), c = 8.298(5)A, β = 98.428(5)A, and z = 2. The space group is P2 1 . The structure was solved by three-dimensional Patterson and Fourier methods, and was refined by least-squares techniques to give a conventional discrepancy factor of R = 0.026; 2435 diffractometer-read reflections were used. The cation was found to be in 9-fold co-ordination to O-1, O-2, O-3, O-2′, O-3′, and four water molecules.

The rate of protium-deuterium exchange, catalyzed by deuterated Raney nickel, on all carbon atoms of four inositols, was measured. The rate of exchange is lowered by methylation of an adjacent hydroxyl group; this effect was studied on seven isomeric, inositol methyl ethers. Correlations between the rate of exchange and the configuration, the conformation, and the site of O -methylation of the inositols have been established.

The 1H- and 13C-n.m.r. spectra of seven inositol methyl ethers were recorded and assigned. They were classified into five types, and the effect of O-methylation on the chemical shifts of each type is discussed.

The 13 C-n.m.r. spectra of the eight diastereomeric inositols and the ten diastereomeric cyclohexanepentols have been recorded and all of the signals have been assigned by a variety of methods. The additive empirical constants used to correlate the configuration of hydroxyl groups with the 13 C-chemical shifts differ, in the latter group, from those derived for the inositols; the removal of one hydroxyl group had altered the “rules” considerably. A better correlation was found between the spectra of the cyclohexanepentols and those of the inositols derived therefrom, in each case, by the addition of an equatorial hydroxyl group.

The 1 H-n.m.r. spectra of all eight diastereomeric 1,6-anhydrohexofuranoses were recorded for solutions in D 2 O at 270 or 300 MHz, and were interpreted first order. For the same solutions, the broad-band decoupled 13 C-n.m.r. spectra of these compounds were recorded at 67.9 or 75.5 MHz, and the 13 C-n.m.r. spectra of the triacetates in ( 2 H)chloroform were tentatively interpreted.

Methyl α- d -idopyranoside and its 2,3-dimethyl ether give only the known 4,6- O -( S )-benzylidene acetals on benzylidenation. Methyl α- d -idopyranoside 2,3-carbonate was prepared, and it gave a small proportion of the ( R )-benzylidene acetal, but, again, the ( S )-isomer was the main product. Surprisingly, in chloroform solution, methyl 4,6- O -( R )-benzylidene-α- d -idopyranoside assumes the 4 C 1 ( d ) conformation, having an axial phenyl group, rather than the 1 C 4 ( d ) form (which would have an equatorial phenyl group). The 4 C 1 forms of the ( R ) and the ( S ) derivatives are stabilized by two hydrogen bonds that can be observed in their n.m.r. spectra. In the presence of water, methyl 4,6- O -( S )-benzylidene-α- d -idopyranoside is mainly in a skew form, but methyl α- d -idopyranoside exists as a mixture of the two chair forms. Several other compounds that have three or more axially attached oxygen atoms have been studied, but none were found to be in a skew form.

The rate of protium-deuterium exchange, catalyzed by deuterated Raney nickel in deuterium oxide, in various positions in methyl glycopyranosides and furanosides has been studied. In general, the exchange process is not highly regio-selective in these compounds. However, conditions were found under which methyl β- d -fructopyranoside can be selectively labelled on C-5, methyl β- d -fructofuranoside on C-3, and methyl β- d -galactopyranoside on C-3 and C-4.

Molecular rotations and molecular-rotation differences are tabulated for the methyl furanosides of all of the aldopentoses, aldohexoses, and hexuloses. The n.m.r. spectra of most of the methyl aldofuranosides have been determined and analyzed, and from the data, the conformations of the glycosides have been deduced. In the d series, the β-pentofuranosides are found to be in the 3 T 2 form, with the methoxyl group quasi -axial and the side-chain quasi -equatorial. The α- d -pentofuranosides are mixtures of two twist forms, or assume an envelope conformation. The correlation between conformation and optical rotation of the methyl furanosides is discussed.

The crystal structure of d -threo-3,4-hexodiulose was determined, and it showed that the crystalline form is the ββ anomer. In solution, the αα anomer is preponderant, although all of its hydroxyl groups are cis to each other. In the crystal, the diulose assumes the endo,exo conformation; in the aqueous solutions of both anomers, the endo,endo form preponderates, whereas the acetates in chloroform are mainly in the exo,exo conformation.

In alkaline solution, periodate ions form complexes with three consecutive hydroxyl groups in an axial-equatorial-axial arrangement but not with three syn -axial hydroxyl groups. Borate ions form complexes with three syn -axial hydroxyl groups but not with the ax  eq  ax sequence. Accordingly, cis -inositol gives a 1,2,3-periodate and a 1,3,5-borate complex. Cations form complexes with either type of conformation, but complex formation provides little energy towards achieving it by ring inversion. Lanthanide ions have been used to establish the sites of complex formation.

The 13 C-n.m.r. signals of the pentitols and hexitols in aqueous solution, and of their acetates in chloroform solution, have been assigned by the use of specifically deuterium-substituted compounds. Qualitative correlations have been established between the chemical shifts and the configuration and preponderant conformation of each of the alditols.

The 13 C-n.m.r. signals of the heptitols in aqueous solution, and of their acetates in chloroform solution, have been assigned by the use of specifically deuterium-substituted compounds. From these spectra, the preponderant conformation of each heptitol has been determined, particularly by comparisons with the spectra of the homomorphous hexitols. The results are in good agreement with the predictions made, on the basis of theoretical considerations, by J.A. Mills ten years ago.

The molecular and crystal structure of d - glycero - l - allo -heptitol has been determined. It crystallises in the orthorhombic space-group P 2 1 2 1 2 with a = 8.399(2), b = 23.484(8), c = 4.664(2) A, α = β = γ = 90°, and Z = 4. The heptitol was found to be in the 3 G − form, which has a 1,3-parallel interaction between C-2 and O-5. In solution, as determined by 1 H-n.m.r. spectroscopy, the heptitol and its hepta-acetate also assume conformations which have a C,O parallel interaction. Such an interaction has also been found to occur in several other heptitols and in hexose dialkyl acetals. Because conformers with such an interaction had been disregarded in the past, the conformations of several heptitols had been wrongly assigned.

From the circular dichroisrm spectra of 23 aldoses and 10 ketoses in aqueous solution, a symmetry rule was derived relating the sign of the n- band of the carbonyl form to the absolute configuration of the sugar. The sign is positive when the configuration of the adjacent chiral center is (S), and it is negative when the configuration is (R). The rule also holds for aldehydo- and keto-sugar peracetates, and for y-lactones substituted with oxygen-containing groups. The magnitude of a mean, molar, dichroic-extinction coefficient for the pure carbonyl forms of aldoses and ketoses was estimated from published c.d. data on the aldehydo- and keto-sugar peracetates and related compounds, which permitted estimation of the proportion of the carbonyl form in the equilibrium mixture for each sugar. D-Glucose had the smallest carbonyl concentration, 0.002% at 20°, in agreement with an earlier, polarographic value. The relationship between carbonyl content and sugar structure and configuration is discussed.

The dimethyl acetals of d -glucose, d -xylose, and l -idose were prepared in 15–25% yield by Fischer glycosidation in the presence of strontium or calcium chloride, whereas no dimethyl acetal was isolated in the absence of these cations. Complexing of these dimethyl acetals with cations was indicated by n.m.r. spectra and by electrophoresis. From the reaction of l -idose, the two (previously unknown) methyl l -idofuranosides were isolated.

Complex formation between galacturonate and glucuronate anions and lanthanide cations has been investigated by the method of lanthanide-induced n.m.r. shifts. Several model compounds have also been studied. It is concluded that the cations are coordinated to the α anomers of these uronate anions at O-5 and one of the carboxylate oxygen atoms; in the β anomers, O-5 is not involved in complex formation.

From the p.m.r. spectrum of 2,3-O-isopropylidene-L-rhamnose, by comparison with that of some model compounds, it was deduced that the aqueous solution in equilibrium contains approximately 25% of α-pyranose, 10% of β-pyranose, 65% of α-furanose, and very little of the β-furanose.

cis -Inositol was synthesized from epi -inositol in seven steps in an overall yield of 25%. The required inversion at C-6 was achieved by oxidation with methyl sulphoxide-acetic anhydride followed by stereospecific reduction.

The p.m.r. spectra of all the fully acetylated pentitols and several fully acetylated hexitols have been analysed. Computation by iterative analysis and recourse to 250-MHz spectra were required in several cases. The vicinal coupling constants were used to determine the conformations of these compounds in solution. The planar zigzag conformation was found to be predominant only in those configurations ( arabino, manno ) which do not possess parallel 1,3-interactions between acetoxyl groups on alternate carbon atoms. The other compounds were found to be mixtures of two or more conformers, none of which has the planar zigzag conformation, except in the case of hexa- O -acetylallitol. The conformations of alditols in the crystalline state and of the alditol acetates in solution are compared.

From the α:β ratio, observed by n.m.r. spectroscopy, of 6-deoxy-5-C-methyl- D -xylo-hexopyranose and of noviose in aqueous solution, the interaction energy of an axial methyl group with an axial hydroxyl group is calculated to be 2.5–2.6 kcal/mole. α-Noviose, in aqueous solution, is a mixture of approx. 70% of the normal and 30% of the alternative chair form.

Oxidation of 2,4-O-benzylidene- D -glucitol with lead tetraacetate, followed by acetylation, gave the two anomers of 1,5-di-O-acetyl-2,4-O-benzylidene-1,3-O-methylene-(1-hydroxy- l -xylitol (5), and a dimeric product (8). After periodate oxidation of 2,4-O-benzylidene- D -glucitol, only one compound, 1,21,3,5-tetra-O-acetyl-2,4-O-benzylidene-2-C-hydroxymethyl- l -threo-pentitol (9), could be isolated in very low yield. Most of the oxidation products appear to be dimeric; the aldehydo or the pyranoid forms of 2,4-O-benzylidene- l -xylose were not obtained.